Ultra-Low Reactive Power Operation and Control Strategy of Hybrid Line Commutated Converter Based on IGCT for HVdc Application

Existing line commutated converter (LCC)-based high-voltage dc (HVdc) systems require large reactive power during operation and reactive power compensation equipment under construction. However, the equipment is expensive and occupies a huge area. In this letter, a novel operation of hybrid line commutated converter based on integrated gate commutated thyristor (IGCT) is proposed to achieve LCC with ultra-low reactive power (LR-LCC), and the corresponding control strategy is developed by utilizing IGCT's active blocking and bidirectional voltage withstanding capability. It can almost eliminate the system's extinguishing angle (?), and the power factor is close to 1. This novel LR-LCC can result in advantages, including a much lower manufacturing cost and volume of reactive power compensation equipment for HVdc application.

Automated summary

Existing line commutated converter (LCC)-based high-voltage dc (HVdc) systems require a large amount of reactive power and costly reactive power compensation equipment. This letter proposes a novel operation of a hybrid LCC based on integrated gate commutated thyristor (IGCT) to achieve LCC with ultra-low reactive power (LR-LCC), utilizing IGCT's active blocking and bidirectional voltage withstanding capability. The LR-LCC almost eliminates the system's extinguishing angle and achieves a close-to-unity power factor. This novel LR-LCC can significantly reduce the manufacturing cost and volume of reactive power compensation equipment for HVdc application.